1. Field of the Invention
The present invention relates to the technique of data communication, particularly to the technique of data communication among a plurality of apparatuses.
2. Description of the Background Art
The development of portable communication apparatuses such as the portable telephone, PHS (Personal Handy-Phone System) and PDA (Personal Digital Assistant) is notable these few years. In accordance with development of these communication apparatuses, intercommunication of the same data among a plurality of communication apparatuses is now carried out.
As the technology related to such data communication, infocast (Journal of The Institute of Electronics Information and Communication Engineers Vol. 82, No. 4, pp. 386-390, April 1999) is known. This communication technique allows the same data to be diffused among a plurality of communication apparatuses as in the game of Chinese whispers by repeating the process of transmitting the data received by a communication apparatus to another communication apparatus.
In a communication system employing the aforementioned communication technique, one data is transmitted to a plurality of communication apparatuses so that a duplicate of one data will exist in many communication apparatuses. In the case where, for example, the communication data corresponds to data of a virtual pet in such a communication system, there will be duplicates of data of the virtual pet in a plurality of communication apparatuses. Therefore, the operation of moving data of a virtual pet around the communication system similar to the moving action of a pet in the real world cannot be realized. In other words, data of a virtual pet cannot be moved from one communication apparatus to another communication apparatus, and then further from that communication apparatus to another communication apparatus.
In the case where one communication apparatus is to be extracted from a plurality of data communication apparatuses by identifying the transmitted data, the aforementioned communication technique will not allow the extraction of one communication apparatus since duplicates of the same one data are respectively present in the plurality of communication apparatuses.